The advent of portable computer systems has placed a premium on providing disk drives of even more reduced size and weight. Disk drive apparatus with a disk of approximately 65 mm (2.56 inches) diameter having an overall height of less than 25.4 mm (1.00 inch) and an overall footprint of approximately 100 mm (4.00 inches) in length by approximately 70 mm (2.80 inches) in width now appear in the market. Exemplary of such a disk drive is U.S. Pat. No. 5,025,336 which issued on Jun. 18, 1991 to Morehouse et al for a "Disk Drive Apparatus". The invention of Morehouse et al includes a low profile spin motor using high energy magnets preferably made of a material including a rare earth, a rotary actuator having a voice coil assembly of reduced height achieved by using a housing as a flux return path for magnetic fields produced by the voice coil assembly, and a base plate of the housing having three-level shape where each level is determined by one or more of components contained within the housing to produce room for electronic components mounted on a surface of a printed circuit board facing the base plate. The printed circuit board having circuitry for controlling various components of the disk drive and the housing including a disk are attached to one another in a stacked relationship that results in a height of approximately 16 mm (0.630 inches) including the printed circuit board. In the disk drive apparatus of Morehouse et al, the rotary actuator contained in the housing has head suspensions attached to an actuator arm on a surface of the head suspension facing away from the disk over which a transducer head attached to the head suspension flies as the disk rotates. Electric connection between the housing and the printed circuit board is accomplished by flexible cables extending through gaps between a lid and the base plate of the housing. The flexible cables are connected to a connector mounted on the surface of the printed circuit board facing the housing. A flexible circuit of flat sheet on which circuitry for the components within the housing are mounted is extended on an inner surface of the base plate of the housing end attached to the base plate.
Also known is the disk drive disclosed in International Application WO 91/02349 which was published on Feb. 21, 1991, and is entitled "Architecture For 21/2 Inch Diameter Single Disk Drive". Disclosed is a disk drive that has a disk of approximately 65 mm (2.56 inches) diameter, an overall height of approximately 17.3 mm (0.68 inches), and an overall foot print of approximately 100 mm in length by approximately 70 mm in width. The housing of the disk drive includes a base plate that provides pins plugged directly into a connector on a printed circuit board for electric connection between the various components contained within the housing and the printed circuit board having circuitry for controlling the components contained in the housing. A spin motor cable is contained within the housing and extended on an inner surface of the base plate to connect a spin motor mounted on the top surface of the base plate to the pins on the base plate. A head suspension is attached to a rotary actuator contained within the housing on a surface of the suspension facing away from the disk surface over which a transducer head attached to the head suspension flies as the disk rotates. A flexible circuit of flat sheet on which circuitry is provided is contained in the housing and extended on the inner surface of the base plate.
Of importance in achieving a reduced height dimension is the height of the components contained within the disk drive housing and, especially, the height of a suspension-actuator assembly. In the prior art suspension-actuator assembly, a head suspension is attached to an actuator arm on one surface of the head suspension facing away from a surface of a disk over which a transducer head attached to the suspension flies as the disk rotates. Accordingly, the highest and lowest movable components in the housing of a disk drive apparatus are the actuator arms to which the head suspensions are attached.
Also of importance in attaining a low profile disk drive is the height profile of components which are mounted on the printed circuit board for establishing circuitry, particularly, a connector for providing an interface between the components contained within the housing and the circuitry established on the printed circuit board. In the prior art disk drives, the connector is mounted on a surface of the printed circuit board facing the housing. Then, the housing and the printed circuit board have to be spaced so as to accommodate the connector. Otherwise, the base plate of the housing facing the printed circuit board has to be recessed so as to accommodate the connector.
Of related interest in producing a disk drive of reduced size is the flexible printed circuit contained within the housing to mount electronic modules thereon for signals to and from the heads and other components within the housing. In the prior art disk drives, the flexible printed circuit of flat sheet is extended on the base plate and attached to the base plate by a screw. The housing of a disk drive is getting smaller and smaller. It becomes difficult to find out room for the flexible printed circuit in the housing where the circuit is free from interference with the rotating disks or the rotating actuator arms.
Another important aspect associated with disk drives of reduced height is a spin cable for electrically connecting a spin motor mounted on a base plate of the housing to the printed circuit board. The spin cable in the disk drive disclosed in WO 91/02349 is positioned on an inner surface of the base plate and connected to the pins extending into the housing from the base plate. The spin cable has to be located on the base plate where the cable does not interfere with the rotating disk and the rotating actuator arm. The housing, however, is getting smaller and smaller. Accordingly, it becomes difficult to find room for the spin cable in the housing of the disk drive. Moreover, adhesive used to attach the spin cable to the inner surface of the base plate of the housing is liable to contaminate or erode the disk. The spin cable in the disk drive disclosed in the patent to Morehouse et al extends through gaps between the lid and the base plate of the housing to the connector mounted on the printed circuit board. But, the gaps are liable to introduce contaminant into the housing.
U.S. Pat. No. 4,933,785 discloses a suspension-actuator assembly in which the head suspension is attached to an actuator arm on a surface of the head suspension facing away from a disk surface over which a head transducer flies as the disk rotates.
U.S. Pat. No. 4,965,684 discloses a spin cable provided on an inner surface of a base plate of a housing of a disk drive.
U.S. Pat. No. 5,025,335 discloses a suspension-actuator assembly in which a head suspension is attached to an actuator arm on a surface of the head suspension facing away from a disk over which a transducer head attached to the head suspension flies as the disk rotates.
Japanese published unexamined patent application No. 60-57584 discloses a suspension-actuator assembly in which a pair of head suspensions are attached to an actuator arm on both upper and lower surfaces of the arm and are offset each other. The suspensions are attached to the actuator arm on the surface of the suspension facing away from a disk over which transducer heads attached to the suspension fly as the disks rotate.
Japanese published unexamined patent application No. 2-294977 discloses a suspension-actuator assembly in which a pair of head suspensions are attached to an actuator arm on the surface of the suspension facing away from a disk over which transducer heads attached to the suspensions fly as the disks rotate.
Japanese published unexamined utility model registration application No. 2-129766 discloses a printed circuit board having a through hole in which an electronic module is provided.